1. Field of the Invention
The invention is based on a method and a device for operating an induction machine.
2. Discussion of Background
The present invention relates to a prior art which is known from DE-A1 3,438,504. In this document, the magnetic flux vector is controlled along a hexagonal path in rotating-field drives with a wide dynamic range and having static converter feed and direct self-control. For this purpose, current and voltage signals are derived from the current feed lines to the induction machine and from these orthogonal flux components are obtained. These are converted into three phase flux components in a coordinate converter, their amplitude is converted to a nominal flux value in a subsequent flux controller or comparator and they are used for controlling the inverter in dependence on a flux-dependent and a torque-dependent change-over device. In this arrangement, unwanted harmonics occur.